There is a guide apparatus having, as shown in FIG. 1, a track rail 101 and a moving block 102 relatively movably attached to the track rail 101 with a multiplicity of rolling elements (balls or rollers) interposed therebetween (there are cases where the track rail 101 is fixed, and the moving block 102 is movable, and where the moving block 102 is fixed, and the track rail 101 is movable). In such a guide apparatus, the moving block 102 has a moving block body 103 mounted astride the track rail 101. End plates 104 are mounted astride the track rail 101 and secured to both ends of the moving block body 103 in the direction of relative movement. Seals 105 are mounted astride the track rail 101 and secured to the respective outer ends of the end plates 104 in the relative movement direction.
The seals 105 prevent foreign matter from entering the moving block 102 through the gaps between the side surfaces of the track rail 101 and the inner peripheral surfaces of both ends of the moving block 102. Because the seals 105 are attached to the moving block 102, no or very small amount of foreign matter such as fine particles can enter the moving block 102 in an ordinary environment when the guide apparatus is used in such a manner that the track rail 101 is installed on a horizontal plane and the moving block 102 is attached to the horizontally extending track rail 101.